Vacuum pump

Abstract

A vacuum pump has a pump case having a gas suction port at an upper part of the pump case and a gas exhaust port at a lower part of the pump case. A stator column extends from a base of the pump case and has an outer circumferential surface. A rotor shaft is rotatably supported in the pump case by the stator column. A spacer is removably integrally connected to the outer circumferential surface of the stator column. The spacer has an outer circumferential surface spaced apart from an inner circumferential surface of the rotor and a through-hole extending form the outer circumferential surface to an inner circumferential surface thereof. A connecting member extends through the through-hole of the spacer and contacts the outer circumferential surface of the stator column to thereby removably integrally connect the spacer to the outer circumferential surface of the stator column.

1. A vacuum pump comprising:
 a pump case having a gas suction port at an upper part of the pump case, a gas exhaust port at a lower part of the pump case, and a base;  
 a stator column extending from the base of the pump case and having an outer circumferential surface;  
 a rotor shaft rotatably supported in the pump case by the stator column;  
 a rotor disposed around the outer circumferential surface of the stator column and integrally connected to the rotor shaft for rotation therewith;  
 a driving motor disposed in the pump case for rotationally driving the rotor shaft; and  
 a spacer removably integrally connected to the outer circumferential surface of the stator column, the spacer having an outer circumferential surface confronting an inner circumferential surface of the rotor and a radial cut extending from the outer circumferential surface to an inner circumferential surface thereof to define a pair of arm portions; and  
 clamping means for clamping the arm portions of the spacer together to tighten and thereby removably integrally connect the spacer to the outer circumferential surface of the stator column.  
 
   
   
     2. A vacuum pump according to  claim 1 ; wherein the clamping means comprises a pair of aligned through-holes extending through respective arm portions of the spacer and a connecting member extending in the through-holes. 
   
   
     3. A vacuum pump according to  claim 2 ; wherein the connecting member comprises a bolt. 
   
   
     4. A vacuum pump according to  claim 1 ; wherein the spacer comprises a generally ring-shaped member surrounding the stator column. 
   
   
     5. A vacuum pump according to  claim 1 ; wherein the outer circumferential surface of the spacer has a profile generally conforming to a profile of the inner circumferential surface of the rotor. 
   
   
     6. A vacuum pump according to  claim 1 ; wherein the spacer is disposed between the stator column and the rotor with a preselected gap disposed between the outer circumferential surface of the spacer and the inner circumferential surface of the rotor. 
   
   
     7. A vacuum pump according to  claim 1 ; wherein the spacer is constructed from a high thermal conductivity metal. 
   
   
     8. A vacuum pump according to  claim 1 ; further comprising a plurality of rotor blades fixed to an outer circumferential surface of the rotor and a plurality of stator blades fixed to an inner circumferential surface of the pump case, the rotor blades and the stator blades being alternately disposed. 
   
   
     9. A vacuum pump comprising:
 a pump case having a gas suction port at an upper part of the pump case, a gas exhaust port at a lower part of the pump case, and a base;  
 a stator column extending from the base of the pump case and having an outer circumferential surface;  
 a rotor shaft rotatably supported in the pump case by the stator column;  
 a rotor disposed around the outer peripheral surface of the stator column and integrally connected to the rotor shaft for rotation therewith;  
 a driving motor disposed in the pump case for rotationally driving the rotor shaft; and  
 a spacer removably integrally connected to the outer circumferential surface of the stator column, the spacer having an outer circumferential surface spaced apart from an inner circumferential surface of the rotor and a through-hole extending from the outer circumferential surface to an inner circumferential surface thereof; and  
 a connecting member extending through the through-hole of the spacer and contacting the outer circumferential surface of the stator column to thereby removably integrally connect the spacer to the outer circumferential surface of the stator column.  
 
   
   
     10. A vacuum pump according to  claim 9 ; wherein the connecting member comprises a setcrew. 
   
   
     11. A vacuum pump according to  claim 9 ; wherein the spacer comprises a generally ring-shaped member surrounding the stator column. 
   
   
     12. A vacuum pump according to  claim 9 ; wherein the outer circumferential surface of the spacer has a profile generally conforming to a profile of the inner circumferential surface of the rotor. 
   
   
     13. A vacuum pump according to  claim 9 ; wherein the spacer is disposed between the stator column and the rotor with a preselected gap disposed between the outer circumferential surface of the spacer and the inner circumferential surface of the rotor. 
   
   
     14. A vacuum pump according to  claim 9 ; wherein the spacer is constructed from a high thermal conductivity metal. 
   
   
     15. A vacuum pump according to  claim 9 ; further comprising a plurality of rotor blades fixed to an outer circumferential surface of the rotor and a plurality of stator blades fixed to an inner circumferential surface of the pump case, the rotor blades and the stator blades being alternately disposed. 
   
   
     16. A vacuum pump comprising:
 a pump case having a gas suction port at an upper part of the pump case, a gas exhaust port at a lower part of the pump case, and a base;  
 a stator column extending from the base of the pump case and having an outer circumferential surface and a portion provided with a through-hole;  
 a rotor shaft rotatably supported in the pump case by the stator column;  
 a rotor disposed around the outer peripheral surface of the stator column and integrally connected to the rotor shaft for rotation therewith;  
 a driving motor disposed in the pump case for rotationally driving the rotor shaft; and  
 a spacer removably integrally connected to the outer circumferential surface of the stator column, the spacer having an outer circumferential surface spaced apart from an inner circumferential surface of the rotor and a step portion extending from the outer circumferential surface of the spacer and having a through-hole disposed in alignment with the through-hole in the portion of the stator column; and  
 a connecting member extending through the aligned through-holes of the spacer and the portion of the stator column to thereby removably integrally connect the spacer to the outer circumferential surface of the stator column.  
 
   
   
     17. A vacuum pump according to  claim 16 ; wherein the connecting member comprises a bolt. 
   
   
     18. A vacuum pump according to  claim 16 ; wherein the spacer comprises a generally ring-shaped member surrounding the stator column. 
   
   
     19. A vacuum pump according to  claim 16 ; wherein the outer circumferential surface of the spacer has a profile generally conforming to a profile of the inner circumferential surface of the rotor. 
   
   
     20. A vacuum pump according to  claim 16 ; wherein the spacer is disposed between the stator column and the rotor with a preselected gap disposed between the outer circumferential surface of the spacer and the inner circumferential surface of the rotor. 
   
   
     21. A vacuum pump according to claims  16 ; wherein the spacer is constructed from a high thermal conductivity metal. 
   
   
     22. A vacuum pump according to  claim 16 ; further comprising a plurality of rotor blades fixed to an outer circumferential surface of the rotor and a plurality of stator blades fixed to an inner circumferential surface of the pump case, the rotor blades and the stator blades being alternately disposed.